> In a message dated 97-11-30 12:31:10 EST, spawn@net-link.net writes:
>
> > I'll jump in here. This is from a materials class I had... Ok
> > here goes,
> > the piston, when it gets cold shrinks/contracts... the cylinder, on the
> > other hand, expands (or, to state it better, the walls contract). If you
> > think about it, for the cylinder to get smaller would require that the
> > block expand. Thus, bigger clearances between piston/cylinder.
>
Surely not. In order to fit valve seats the head is heated and the seat
cooled.
The root cause of shrinking and expanding with heat is to do with the vibration
of
molecules and atoms. More heat = more movement = more space between atoms.
With
the cylinder block the whole thing shrinks on cooling - metal and spaces.
PaulH.
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